Startup of a reactive distillation process with a decanter

The startup of a reactive distillation process for the production of propyl acetate including a decanter is studied. A simulation model is presented which describes the whole startup from a cold and empty state and takes into account the liquid phase split in the decanter. The simulation model is successfully validated with own dynamic experimental data. Different startup strategies are developed and analysed in simulation studies showing the high influence of the initial charging of decanter and reboiler on the startup time

Sonic limitations and startup problems of heat pipes

Introduction of small amounts of inert, noncombustible gas aids startup in certain types of heat pipes. When the heat pipe is closely coupled to the heat sink, the startup system must be designed to bring the heat sink on-line slowly

The Kauffman Index: Startup Activity National Trends - 2016

This report provides a broad index measure of business startup activity in the United States. It is an equally weighted index of three normalized measures of startup activity:The Rate of New Entrepreneurs in the economy, calculated as the percentage of adults becoming entrepreneurs in a given month.The Opportunity Share of New Entrepreneurs, calculated as the percentage of new entrepreneurs driven primarily by "opportunity" vs. "necessity."The Startup Density of a region, measured as the number of new employer businesses normalized by total business population

SSthreshless Start: A Sender-Side TCP Intelligence for Long Fat Network

Measurement shows that 85% of TCP flows in the internet are short-lived flows that stay most of their operation in the TCP startup phase. However, many previous studies indicate that the traditional TCP Slow Start algorithm does not perform well, especially in long fat networks. Two obvious problems are known to impact the Slow Start performance, which are the blind initial setting of the Slow Start threshold and the aggressive increase of the probing rate during the startup phase regardless of the buffer sizes along the path. Current efforts focusing on tuning the Slow Start threshold and/or probing rate during the startup phase have not been considered very effective, which has prompted an investigation with a different approach. In this paper, we present a novel TCP startup method, called threshold-less slow start or SSthreshless Start, which does not need the Slow Start threshold to operate. Instead, SSthreshless Start uses the backlog status at bottleneck buffer to adaptively adjust probing rate which allows better seizing of the available bandwidth. Comparing to the traditional and other major modified startup methods, our simulation results show that SSthreshless Start achieves significant performance improvement during the startup phase. Moreover, SSthreshless Start scales well with a wide range of buffer size, propagation delay and network bandwidth. Besides, it shows excellent friendliness when operating simultaneously with the currently popular TCP NewReno connections.Comment: 25 pages, 10 figures, 7 table

Some Remarks on Wittgenstein’s Philosophy of Mathematics

Drawing mainly from the Tractatus Logico-Philosophicus and his middle period writings, strategic issues and problems arising from Wittgenstein’s philosophy of mathematics are discussed. Topics have been so chosen as to assist mediation between the perspective of philosophers and that of mathematicians on their developing discipline. There is consideration of rules within arithmetic and geometry and Wittgenstein’s distinctive approach to number systems whether elementary or transfinite. Examples are presented to illuminate the relation between the meaning of an arithmetical generalisation or theorem and its proof. An attempt is made to meet directly some of Wittgenstein’s critical comments on the mathematical treatment of infinity and irrational numbers

Beyond Metropolitan Startup Rates: Regional Factors Associated with Startup Growth

Understanding what fosters -- and hinders -- firm formation and growth at the metropolitan level across the United States is a challenge. Entrepreneurship can be measured by a variety of indicators, and they each can tell somewhat different stories. Furthermore, because entrepreneurship can refer to the growth of firms from a startup stage to mid- or large-scale, no one dataset covers the full range of companies that fall in this category. This report contributes to the Kauffman Foundation's recent series of analyses on the rate of business creation in metropolitan areas. Going beyond identifying metropolitan areas with higher rates of entrepreneurship, we analyze what regional factors are associated, or unassociated, with entrepreneurial activity. Understanding what drives entrepreneurship at the regional level -- especially high-growth business creation -- will help policymakers and entrepreneurship supporters know where to invest their efforts

Give Me Your Entrepreneurs, Your Innovators: Estimating the Employment Impact of a Startup Visa

The idea of visas for immigrant entrepreneurs has bounced around the country for many years, and even has been introduced into Congress on more than one occasion. The most recent is Startup Act 3.0, a bipartisan bill recently introduced into the U.S. Senate that, among other things, includes a Startup Visa. In this current incarnation, the new Startup Visa would make available a fixed pot of 75,000 visas for individuals who start companies. Initial eligibility would be restricted to individuals who already are in the United States on either H-1B visas or F-1 student visas. Once the Startup Visa is issued, further requirements are imposed in the first year. During that time, the entrepreneur must register a business, employ at least two full-time, non-family employees, and invest or raise an investment of at least $100,000. If, after one year, those requirements are met, the entrepreneur gets three additional years on the visa. During that three-year period, the entrepreneur must employ at least five full-time, non-family employees. The original two employees count toward these five, which means the business essentially must hire one person per year after the first year of operation. At the end of three years, the entrepreneur may apply to have the conditional status removed.This report attempts to estimate the impact on job creation that enactment of such a Startup Visa would have. Calculations suggest that a Startup Visa could create anywhere from 500,000 to 1.6 million jobs over the next ten years. Because of the assumptions and methods used, these estimates are considered very conservative, low-end estimates